<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_BOM操作</title>
</head>
<body>
    <button onclick="alert('请先登录!')">弹出警告框</button>
    <button onclick="confirm('是否确定删除?')">弹出确认框</button>
    <script>
        console.log(parseInt(6.1));
        console.log(parseInt(6));
        console.log(parseInt(6.9));
        console.log(parseInt('6.99'));
        console.log(parseInt('hhh'));

        console.log(parseFloat(6.1));
        console.log(parseFloat(6));
        console.log(parseFloat(6.9));
        console.log(parseFloat('6.99'));
        console.log(parseFloat('hhh'));

        //isNaN()判断参数是否为非数字，如果参数为非数字返回true，否则返回false
        console.log(isNaN(6.1));
        console.log(isNaN(6));
        console.log(isNaN(6.9));
        console.log(isNaN('123'));
        console.log(isNaN('hhh'));
    </script>

</body>
</html>